THE EYE, 



99 



2. Cut all round the cornea, with stout scissors, about J inch 

 from its junction with the sclerotic : remove the cornea : take care 

 not to squeeze the eye, or the lens will he driven out instantly: note: 



i. The aqueous humour : the transparent watery fluid 

 fining the anterior chamber of the eye, and 

 escaping when the cornea is removed 

 The lens- 



11 



Fig. 18. A diagrammatic section through the human eye passino- 

 through the centres of the cornea and lens, and through the yellow spot 

 and point of entrance of the optic nerve. 



A, anterior chamber : Ar, central artery of retina : B, blind spot • 

 C, cornea: Ch, choroid: CP, ciliary processes : H, hyaloid membrane' 

 enclosing the vitreous humour : I, iris : L, lens : O, optic nerve : P, posterior 

 chamber : R, retina : S, sclerotic : SL, suspensory.ligament : Y, yellow spot. 



3. Pass the handle of a scalpel under the cut edge of the cornea, 

 betiveen it a7id the iris, and carefully separate the sclerotic from 

 the choroid the whole way round for a distance of about half an 

 inch beyond the edge of the cornea. Make four radial cuts, equi- 

 distant from one another, through the margin of the cornea and 



